Thiocyano-alkyl ethers of alkylphenols



Patented Jan. 2, 1940- mrnazo STATES. PATENT OFFICE TBIOOYANO-ALKYL ETHEBS F ALKYLPHENOLS Gerald B. Coleman and Clarence Moyle, Midland, Micln, assignors to The Dow Chemical Company, Midland, Mich, a corporation of Michigan No Drawing. Application October 28, 1938,

. Serial No. zs'lioss 13 Claims.

The present invention concerns a new class of compounds, namely, thethiocyano-alkyl ethers of alkylphenols, wherein the sum of the carbon atoms in the allrvl groups attached to the benzene nucleus is at least 2.

We have prepared compounds of the aforementioned class, determined certain physical properties thereof whereby they may be readily identified, and found that they are useful as insecticidal toxicants, particularly when dissolved in petroleum distillate fractions. These compounds are, for the most part, viscous, high boiling, water white liquids substantially insoluble in water, soluble in most petroleum distillate fractions, and somewhat soluble in organic solvents generally. 5 Our new compounds may be prepared by reacting a halo-alkyl ether oi an alkyl-phenol with an alkali metal thiocyanate in presence 0t alcohol. For example, a halo-allql ether of an alkyl- 7 phenol such as beta-(4-tertiary-butyl-phenoxy) ethyl chloride and potassium thiocyanate are dispersed in absolute alcohol and the resulting mixture heated. to its boiling temperature and under reflux for a period of time sufilcient to accomplish the reaction. The reaction temperature is generally between 75 and 90 0., although somewhat lower or higher temperatures may be employed, the reaction being carried out under be recovered by extraction with a suitable sol-.

vent, as benzene, the extract being fractionally distilled. In an alternate'procedure the water- 1 immiscible layer may be separated as by decantation, washed with water, and used as an insecticidal toxicant without further purification.

The halo-alhl ethers employed as reactants in the preparation of our new compounds can be obtained by reacting suitable metal phenolates with the "dihalo-aliphatic hydrocarbons under conditions of temperature and pressure that favor the replacement of a single halogen atom tofremove undissolved potassium bromide, and

by the alkyl-phenoxy group. Co-pending application Serial No. 139,581, filed April 28,1937, by Coleman et a1. describes the preparation or certain of these halo-alkyl ethers.

The following examples describe in detail the preparation of a number of compounds falling within the scope of our invention, but are not to be construed as limiting the same:

Bramble 1 A mixture of 3-9 grams (0.183 mol) of betachloro-ethyl ether of 4-tertiarybutyl phenol (boiling point 107 to 108 C. at 2 millimeters pressure); 15.4 grams (0.19 mol) of sodium thiocyanate, and grams of absolute alcohol was heated to its boiling temperature of to 87 C.

and under reflux for 30 hours. Thev mixture was then distilled to remove the major part of the alcohol solvent and the residue 'poured into an excess of water with stirring. A water-immiscible 20 layer was separated from the water. mixture byextraction with benzene, and the extract washed with'water, dried over magnesium sulfate and fractionally distilled. 18 grams of beta-thiccyano-ethyl ether of 4-tertiarybuty'l phenol was thereby obtained. as a colorless liquid boiling at 158-163 C. at 2.5 millimeters pressure and having the specific gravity 1.073 at 20/4 C. A 3 per cent solution of this compound in kerosene, when tested by the Feet-Grady method substantially as described in Soap, 8, No. 4 (1932), gave a knockdown of 97 per cent in 10 minutes 'anda kill 01 81 per cent in 48 hours againstthree-day old house flies.

Example 2 368.2- grams (1.4 mols) of beta-bromo-ethyl ether of. carvacrol (boiling point to Or at 10 millimeters pressure), 135 grams (1.4 molsi of potassium thiocyanate, and. 500 milliliters'oi' absolute alcohol were mixed together and heated at 85 C., the refluxing temperature of the mixture, for 6 hours. The reaction mixture was thereafter cooled to room temperature, filtered fractionally distilled, whereby there was obtained the beta-thlocyano-ethyl ether of carvacrol in 62 f per cent yield as a pale, yellow colored oil boil- 4 ing at 189 to 196 C. at 10 millimeters pressure,

and having a specific gravity or 1.076 at 25/.4 C. A 3 per cent solution ,of this compound in kerosene, when tested according to the Feet-Grady method gave a knockdown in 10 minutes of 100 per cent and a kill in 48 hours of 92 percent of three-day old house flies;

Example 3 mixed ether product was reacted with potassium thiocyanate in absolute alcohol substantially as described in Example 2. Upon fractional distillation of the crude reaction product, a mixture of beta-thiocyano-ethyl ethers of common wool phenols was obtained boiling at 190 to 195 C. at 15.3 millimeters pressure and having a specific gravity of 1.147 at 25l4 C. A 3 per cent solution of this mixture in kerosene, when tested as described in the preceding examples, ave a knockdown in 10 minutes of per cent and a kill in 48 hours of 93 per cent of three day old house flies.

Example 4 Equimolecular proportions of potassium thlocyanate and the beta-l romo-ethyl ether of a mixture of isomeric xylenols were dissolved in alcohol and reacted together as described in Example 2, to obtain the betaFthiocyano-ethyl ethers of the xylenol mixture as a pale yellow liquid boiling at 175 to 190 C. at 10 millimeters pressure and having a specific gravity of 1.142 at 25l4 C.

In a similar manner, other halo-alkyl ethers of alkyl phenols were reacted with the alkali metal thiocyanates to obtain the corresponding thiocyano-alkyl ether compounds. The following are representative of the thiocyano-alkyl ethers obtained:

Gamma-thiocyano-propyl ether of 2,4-ditertiarybutyl phenol, a colorless liquid boiling at 173 to 175 C. at 2 millimeters pressure and having a specific gravity of 1.140 at 30l4 C.

This compound was prepared by reacting the gamma-chloro-propyl ether of 2,4-ditertiarybutyl phenol (boiling point 153 to 154 C. at 4 r with potassium thlomillimeters pressure) cyanate.

Beta-thiocyano-ethyl ether of thymol, a pale yellow liquid boiling at 173 to 176 C. at 5 millimeters pressure and having the specific gravity 1.062 at 25l4 C. This compound was prepared by reacting the beta-bromo-ethyl ether of thymol (boiling point to C. at 5 millimeters pressure) with potassium thiocyanate. A 3 per cent solution of this compound in kerosene, when tested as described in the preceding examplesgave a knockdown in 10 minutes of 100 per cent and a kill in 48 hours of 83 per cent of three-day old house flies.

Beta-thiocyano-ethyl ether of 2-methyl-4- tertiarybutyl phenol, a viscous liquid boiling at 195 to 198 C. at 10 millimeters pressure, and having a specific gravity of 1.062 at 25l4 C. This compound was prepared by reacting the beta-bromo-ethyl ether of 2-methyl-4-tertiarybutyl phenol (boiling at to 154 C. at 10 millimeters pressure) with potassium thiccyanate.

Beta-thiocyano-ethyl ether oi 2-methyl-4- cyclohexyl phenol, a yellow liquid boiling at 210 to 220 C. at 6.3 millimeters pressure and having a. specific gravity of 1.100 at 25/4 C. This compound was prepared by reacting the beta-bromoethyl ether of 2-methyl-4-cyclohexyl phenol (boiling at 180 to 200C. at 9 millimeters presethers of alkylphenols to obtain the thiocyanqalkyl ethers of such phenols as 2-ethy1 phenol, 3-isopropyl phenol, 4-secondary-buiarl phenol, 4- normal-hexyl phenol, 3,5-dimethyl phenol, 2,4,6- trimethyl phenol, 2-methyl4,6-di-lsopropyl phe nol, 4-tertiaryoctyl phenol, 2-cyclohexyl-4-ter- 'tiarybutyl phenol, 3-cyclohexyl-4-methyl phenol, and the like. The ether compounds which' may be so prepared include betathiocyano-ethyl ethers, beta-thiocyano-propyl ethers, gammathiocyano-propyl ethers, gamma-thiocyanoisobutyl ethers, thiocyano-pentyl ethers, and the like.

-The above thiocyano-alkyl ethers of the alkyl phenols are particularly valuable as insecticidal toxicants for inclusion in petroleum distillate type spray compositions. They are superior for this use over the thiocyano-alkyl ethers of phenol, for example, because of the greatly increased solubility of the ethers of the alkylphenols in such petroleum distillate fractions as kerosene and the The compounds with which the present invention is particularly concerned are thrme having the formula 1 R-O-Cdhn-SCN wherein n represents an integer from .2 to 5, inclusive, and R represents an .alkylated phenyl radical containing at least 8 carbon atoms.

We claim: r 1. A compound having the formula ROCH2u CN 2. A thiocyano-alkyl ether of an alkyl phenolwherein the sum of the carbon atomsv in the alkyl groups attached to the benzene nucleus is at least 2.

3. A compoimd having the formula wherein n is an integer from 2 to 5, inclusive, X

00-0 nib-son wherein n is an integer from 2 to 5, inclusive, one X represents an alkyl radical, 'and the other X represents a member of the group consisting of alkyl cycloalkyl, and hydrogen, the sum of the carbon atoms in the X groups being at least 2.

5. A compound having the formula wherein n is an integer from 2 to 5, inclusive, and each X represents an alkyl radical.

6. A compound having the formula Qo-cJh-scw x wherein n is an integer from 2 to 5, inclusive,

and X represents an alkyl group containing at least 2 carbon atoms.

7. A compound having the formula wherein R represents an alkylated 'phenyl rad ical containing atleast 8 carbon atoms. H 8. A beta-thiocyano-ethyl ether of an alkyl phenol wherein the sum of the carbon atoms in the alkyl groups attached to the benzene nucleus is at least 2.

9. A compound having the formula wherein X reprsents an alkyl radical and each Y representsa member of the group consisting of -alkyl, cycloalkyl, and hydrogen, the sum of the carbon atoms in the X and Y groups being at least 2. i

10. A compound having the formula wherein X represents an alkyl group containing at least 2 carbon atoms.

12. Beta-thiocyano-ethyl ether of carvacrol.

-13. Beta-thiocyano-ethyl ether of 4-tertiarybutyl phenol.

GERALD H. COLEMAN. CLARENCE L. MOYLE. 

